re: Couples that always whisper around one another

It just means they are sharing information they don't want shared with the rest of the class. You have two choices: either call them out on it and explain to them why you think this sort of behavior is disrespectful or just ignore it and not turn into a little bitch over something so inconsequential and petty. Whining about it to strangers on the internet behind those couples' backs isn't solving anything.